This study aimed to examine the effect of an intensive vocabulary intervention embedded in e-books on the vocabulary skills of young Spanish-English speaking English learners (ELs) from low-socioeconomic status backgrounds. Children (N = 288) in kindergarten and 1st grade were randomly assigned to treatment and read-only conditions. All children received e-book readings approximately 3 times a week for 10-20 weeks using the same books. Children in the treatment condition received e-books supplemented with vocabulary instruction that included scaffolding through explanations in Spanish, repetition in English, checks for understanding, and highlighted morphology. There was a main effect of the intervention on expressive labeling (g = 0.38) and vocabulary on the Peabody Picture Vocabulary Test-Fourth Edition (g = 0.14; Dunn & Dunn, 2007), with no significant moderation effect of initial Peabody Picture Vocabulary Test score. There was no significant difference between conditions on children's expressive definitions. Findings substantiate the effectiveness of computer-implemented embedded vocabulary intervention for increasing ELs' vocabulary knowledge. Computer-assisted vocabulary instruction with scaffolding through Spanish explanations, repetitions, and highlighted morphology is a promising approach to facilitate word learning for ELs in kindergarten and 1st grade.